Optical properties of ferrites through their magnetic ordering and spin-reorientation temperatures

Iron oxides have attracted a great deal of attention due to their high magnetic ordering temperatures and semiconducting band gaps, the combination of which is very attractive for applications. In this work, we investigate band gap behavior in charge-ordered LuFe$_{\mathrm{2}}$O$_{\mathrm{4}}$ and its cousin LuFeO$_{\mathrm{3}}$, showing that the latter is robust with temperature through the 130 K spin-reorientation and 440 K Neel transitions, and compare our findings with electronic structure calculations. Time permitting, we will discuss the spin polarized nature of the bands that form the leading edges of the gaps.